✨ Light Year Distance Calculator
Enter a distance in light years to convert it to kilometers, miles, astronomical units (AU), and parsecs.
What is a light year?
A light year is the distance light travels in one Julian year through a vacuum, used because the distances between stars and galaxies are far too large to conveniently express in kilometers or miles alone.
The formula
One light year equals exactly 9,460,730,472,580.8 km (using the speed of light, 299,792,458 m/s, times the number of seconds in a Julian year). This calculator converts your input light-year distance into kilometers, miles, astronomical units (1 AU = average Earth-Sun distance), and parsecs (1 parsec = 3.26156 light years), the default value shown is the distance to Proxima Centauri, the nearest known star to our Sun.
These are precise unit conversions based on the standard light year definition. This calculator is for general astronomy reference and educational purposes.